Patent · US Expired

Image forming apparatus

US7123862B2 · kind B2 · utility

31Cited by
3References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 27, 2004
Grant dateOct 17, 2006
Priority date
Expiry dateApr 20, 2025

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G9/08782
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

In an image forming apparatus having at least an amorphous silicon photosensitive member, a magnetic toner developing means and a color developer developing means, the magnetic toner has a weight-average particle diameter (D4) of from 4.0 μm to 10.0 μm and a ratio thereof to number-average particle diameter (D1), D4/D1, of from 1.0 to 2.0, and the number of magnetic particles not passing through a mesh with an opening of 34 μm which are contained in the unit volume of the magnetic toner is from 3.5 to 105. This image forming apparatus can not easily cause faulty cleaning performance even in using the magnetic toner and the non-magnetic color toners in combination and has superior environmental stability and running stability even where toners made to have small particle diameter are used or process speed is high.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.